Re: delete cascade

From: paul c <toledobythesea_at_oohay.ac>
Date: Tue, 17 Apr 2007 12:29:24 GMT
Message-ID: <E43Vh.87138$6m4.7462@pd7urf1no>

paul c wrote:
> Bob Badour wrote:

...

>> No. One states that deleting the invoice automatically deletes any 
>> items that exist. The other states that one may not delete an invoice 
>> when any items exist.

>
>
> Thanks, that clears up my confusion. Still, it strikes me as more an
> attitude than a logical interpretation. If I could, I'd rather wonder
> how to declare a reference from the logical complement of invoices to
> the complement of items!

Sorry, I think I put that wrongly. Maybe the constraint that "one may not delete an invoice when any items exists would look something like "(NOT Invoices{Invoice#}) AND Items{Invoice#} = FALSE", ie., a reference from the complement of invoices to items.

p Received on Tue Apr 17 2007 - 07:29:24 CDT